I am surprised the ratings aren't higher for this episode - I thought it was the funniest episode in the entire run.
From Sam hiding her engagement to Hank, to Angela making Tony think about what's going on, to Tony finding Hank's parents still think he's going to medical school instead of leaving it to be a puppeteer ("I know something you don't know!") this episode sparkled.
The eighth season was supposed to feature Tony and Angela getting married about this time, then spend the last couple months as a married couple, and this episode was slated to be near the very end. But syndication concerns (unwarranted, in my opinion) made the show change course, and this episode was bumped into an earlier sweeps month.
I was told think by a production assistant who was very surprised at the change in course.